Lecture #3

Biological Diversity

Term given to the variety of life on Earth. It is the variety withing and between all species of plants, animals, and microorganisms.

Species Diverstiy

Refers to the number and abundance of species at a particular location. Consists of two components: Species richness and species evenness.

Species Richness

Number of species at a particular location

Genetic Diversity

Refers to the number of different alleles of all genes and the frequency which they appear

Genetic Variation

Capacity to change and adapt to new environments.

Early Earth

Characterized by high temperatures, volcanic eruptions, a concentration of ammonia, methane, carbon dioxide, and lack of oxygen. First organisms emerged 3.5 BYA

Origin of Life

Oparin suggested the organic compounds could have undergone a series of reactions leading to more and more complex molecules. Proposed that molecules formed colloid aggregates.

Woese

Defined three domains of life

Prokaryotes

Oldest groups of organisms. 90% not described. Two domains. Bacteria and Archaea

Bacteria

Mostly beneficial. Fix nitrogen, and decompose nutrients. Aid is digestion.

Microbiome

Consists of 10-100 trillion symbiotic microbial cells harbored by each person.

Photosynthetic Bacteria

Bacteria that can use photosynthesis. Added O2 to the atmosphere, leading to the formation of the ozone layer

Cyanobacteria

Blue-Green algae. Aquatic

Eukaryotic Cells

Has a nucleus and organelles. Appeared first in microfossils 1.5 BYA. They are multicellular and specialize. Allows for differentiation of cells into tissues.

Endomembrane System

These membranes……

Endosymbiosis

…

Multicellularity

Leads to cell specialization.

Unicellular Organisms

Consist of half of the biomass on Earth. Strong limits in regard to specialization.

S3xual Reproduction

Increases genetic diversity. Allows of meiosis, and cross fertilization.

Aquatic

Most evolutionary innovations occurred while life was this.

Rapid Radiation

Occurred in the Mesozoic-Cenozoic